1. Field of the Invention
The present invention relates to battery operated light units typically situated atop barricades placed along the road-side to mark construction zones, road hazards or to otherwise warn passing motorists. More particularly, the present invention is directed to an apparatus and method for extending the useful life of the batteries powering the light unit.
2. Background Art
Barricade mounted warning light units are required to be used in virtually every road construction project to alert motorists generally to the presence of the construction zone and particularly to the presence and location of a specific hazard. Typically when on, these light units operate in either a "steady burn" mode or in a flashing mode. In the flashing mode, circuitry driving the light source causes the light to repeatedly turn on and off at a desired rate typically between 55 and 75 times per minute. In the "steady burn" mode, in order to prolong battery life, the light source is not truly constantly on, but rather, the light source is driven by circuitry which flashes the light unit on and off very rapidly. The frequency of the flash rate is in fact so high that the flashing light is perceived by the human eye to be a constantly illuminated light.
In many states, municipalities, counties and other governmental entities have laws and/or regulations which govern the operation of these illuminated barricades. Many entities, if not all, require that the light atop the barricades operate from at least dusk to dawn. Other regulations require that the light, when in flash mode, flash at a certain rate, such as between 55 and 75 times per minute. Other requirements are directed to the minimum lumens (or candles) of illumination output by the light unit as well as the direction of diffusion of the light emitted.
As with any battery-operated device, it is known that after a certain length of use the battery will be depleted and the device will no longer operate. In a lighting application it might be assumed that the light unit will remain lit until all of the battery energy is exhausted with, however, a decrease in light output corresponding to a decrease in battery voltage. In fact, in most instances where electronic circuitry is controlling the operation of the light, a certain minimum voltage is required to operate the control circuitry itself. When the battery energy falls below a certain voltage the control circuitry will cease to operate and the light will no longer function necessitating replacement of the battery. However, it is noted that in many cases when the light has ceased to function there does in fact remain useful energy in the batteries removed from such barricade light units. In addition to wasting money by prematurely disposing of otherwise useful batteries, a worn-down battery and non-functioning warning light may lead to a hazardous condition where passing motorists are unable to see the warning barricade and as a result are injured resulting in potential legal liability to the barricade owner/operator.
Accordingly, it is an object of the present invention to provide an apparatus and method for extending useful life of the barricade warning light unit.
It is an associated object of the present invention to provide a warning light which automatically switches from a flashing or "steady burn" mode of operation to a constant on mode of operation.
These and other objects of the present invention will become apparent in light of the present specification, claims and drawings.